Adding A Sign:
To add a sign on the map, simply click anywhere on the map and a yellow sign will instantly appear (indicated by arrows). To delete the yellow sign, click on the sign located on the right of the map (indicated by the star).
The Lime Green Arrow:Double click on that sign to set off the Lime Green arrow that guides you to your destination.
A red mark pops up above the sign, but this doesn't make the green arrow dissappear, if you triggered it. To make the lime green arrow gone, either go to the destination, go inside if you are outside, or go outside if you are inside.